1. Field of the Invention
This invention relates to an apparatus for disassembling a hydraulic valve lifter used in automobile engines.
2. Description of the Prior Art
Many modern automobile internal combustion engine designs have replaced the mechanical valve lifters with "no-lash" hydraulic valve lifters. The typical hydraulic valve lifter employs a cylindrically shaped body containing a hydraulic fluid and a plunger movable therewithin. The plunger includes on its upper face a cup-like receptacle for the valve stem or push rod, and on its lower face a check valve which allows the oil to move internally between the plunger cavity and a subjacent cavity inside the cylindrical housing, with the motion of the hydraulic fluid absorbing the lost motion or lash in the valve operating mechanism.
Occasionally, the internal plunger becomes jammed within the cylindrical housing due to an accumulation of incomplete combustion products and contaminated lubricating oil. When the plunger becomes jammed the valve operating mechanism becomes noisy and the hydraulic valve lifter must be replaced. Also, when rebuilding older engines it is advisable to disassemble the hydraulic valve lifter assembly to remove any accumulated contaminates therein. In both of these instances when disassembly is thwarted by a stuck plunger it is necessary to discard the old hydraulic valve lifter and insert a new replacement. This replacement is unnecessarily expensive since the old valve lifters can be quickly, easily and inexpensively disassembled, cleaned and inspected if an inexpensive and reliable tool could be utilized in the disassembly thereof.
The C. B. Clarke U.S. Pat. No. 2,754,574 and J. T. Clark U.S. Pat. No. 2,877,542 disclose similar devices for inserting a tool within the valve lifter and forcing a grease or other hydraulic fluid behind the plunger and thereby forcing the plunger outwardly from the cylindrical housing. This method is satisfactory, but requires a source of hydraulic fluid or grease under high pressure and also leaves the hydraulic lifter assembly quite messy after the disassembly project has been completed.
Tutino in U.S. Pat No. 3,681,838 discloses an invention for removing the hydraulic valve lifter from the engine or head block assembly. This invention includes a device which is inserted into the first interface circumferential edge of the cylindrical housing for the hydraulic valve lifter. The device is then expanded therewithin such that grasping lips around the circumferential surface thereof communicate with the first interface circumferential edge of the valve lifter allowing the hydraulic valve lifter assembly to be withdrawn from the engine block or head assembly. However, this invention is described as only being useful for removing the hydraulic valve lifter assembly from the engine and not for disassembling the hydraulic valve lifter assembly for cleaning and repair. Furthermore, this device couples to the hydraulic valve lifter housing and not to the movable plunger therein.
A tangentially related invention is disclosed by Kanda in U.S. Pat. No. 3,823,462 relating to a tool to facilitate the extraction of broken components of a sprinkler system from the interior of conduit pieces.